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My home was built in 1929 therefore there are no return ducts on the 2nd floor. I received six estimates for a new split system. The furnace is a 2stage VSF @93% 70K. The AC is a 14 seer unit 2.5 ton.

2nd floor
There are three 7 supply ducts one for each bedroom. There is no supply in the hallway. One of the contractors was more concerned about having adequate (a/c) cold air supply and suggested adding an 8 supply in the ceiling in the hallway.

He also said a return would not be needed with enough supplys (4) on the 2nd floor with all doors open to allow for air circulation. One main large return ( 30x 20) would be installed in the floor on the first floor with duct attached to the furnace in the basement.

This is an old house with not many options for return ducts to the 2nd floor. Most of the other contractors agreed with an 1190sf a return duct would not be needed 2nd floor. I not worried about the heat its the hot humid air in the rooms during the summer with no return.

Find an option for a return upstairs and dont use that contractor to do your work. Any contractor who says that is a hack. You will roast in the summer if you dont put a return upstairs. Returns upstairs are important. If possible put one in every bedroom. The reason for this is in case you sleep with the doors closed or close the doors at all for anything. If you cant put one in every bedroom put one in the hallway. If you can put a supply there you can put a return there. What size return will depend on the size of the upstairs.

Returns are very important. They are what keeps the air circulating. This in turns moves the hot air out of the conditioned space so it can stay cool. I agree that if you can run new supply, then you can run a few new returns.

It doesnt matter how big your "path" is. You can put 15 supply registers upstairs but if you dont have enough return then it isnt going to matter. Example 800 cfm return trying to feed 10, 6 inch supply registers. Supply equals 1000 and return is only 800 so therefor you are only going to get 800 out of the supply.

I have to agree with dash on this one. As long as there is a good amout of return on the first floor and a claer path it should work. Idealy a return on the second floor would work better but some times it isnt feasable and to put a small 7 or 8 in return would be a waist of time. If this contractor feels there is no way to get enough return to the second floor and can install more supply then that doesnt mean he is a hack (not goog to call are own hacka either) means he is just trying to give you the best job he can with out taring your house apart

I'm a hack I guess. Dash is right, you have to get enough supply air to the upstairs for it to have a chance of working. It doubt that you will be happy with the upstairs unless you use a zoned system or two seperate systems. Forcing air upstairs is hard to do unless it is well thought out before hand or you have a seperate zone for it.

No amount of return will solve your problem if the cold air is not getting there to begin with.

Originally posted by bspiner13 My home was built in 1929 therefore there are no return ducts on the 2nd floor. I received six estimates for a new split system. The furnace is a 2stage VSF @93% 70K. The AC is a 14 seer unit 2.5 ton.

2nd floor
There are three 7 supply ducts one for each bedroom. There is no supply in the hallway. One of the contractors was more concerned about having adequate (a/c) cold air supply and suggested adding an 8 supply in the ceiling in the hallway.

He also said a return would not be needed with enough supplys (4) on the 2nd floor with all doors open to allow for air circulation. One main large return ( 30x 20) would be installed in the floor on the first floor with duct attached to the furnace in the basement.

This is an old house with not many options for return ducts to the 2nd floor. Most of the other contractors agreed with an 1190sf a return duct would not be needed 2nd floor. I not worried about the heat its the hot humid air in the rooms during the summer with no return.

Any info would be greatly appreciated

[Edited by bspiner13 on 10-12-2005 at 11:35 PM]

Better find a way to get some kind of return upstairs, because, why do they call it (air) conditioning, the ability to make air changes per hour to remove the heat and humidity from a conditioned space.

New Installation

I decided to go with the contractor who suggested more supply on the 2nd floor. Total time for installation was about 2 working days 15hrs. Thanks to all for you information.
Click the link for some pics.